We have seen this before with tons of mainstream devices, smartphones are no different. You have the incumbents designing and engineering something main stream while other manufacturers will come in and sell something similar with slightly less features for vastly lower costs. I think we are coming close to "peak smartphone development" where it's at the point they are good enough for almost everything we want them to do. I bought an SG 7 and quite frankly, it will be the last 800$ phone I ever buy. Nothing revolutionary, just iterative at this point.
Apple and Samsung are at the top end of a saturated market. Really nowhere to go but down unless they are only interested in market share with lower end phones they can sell at lower costs. Not sure if this is the market they want to chase, especially Apple.